Battery, battery pack, battery charger, and battery charging system

ABSTRACT

Disclosed herein is a battery. The battery includes a contactless communication control block configured to execute contactless communication as a transponder and a reader/writer which are based on electromagnetic induction. The battery further includes an antenna configured to execute the contactless communication as the transponder; and an antenna configured to execute the contactless communication as the reader/writer. The battery further includes a battery control block configured to control a charge operation of a cell block. The contactless communication control block communicates, in a contactless manner, a charge state of the cell block supplied from the battery control block.

BACKGROUND

The present disclosure relates to a battery, a battery pack, a batterycharger, and a battery charging system and, more particularly, to abattery, a battery pack, a battery charger, and a battery chargingsystem which are configured to execute, on the basis of a simplestructure, charge/discharge control on battery cells even if the numberof battery cells increases.

Charging a battery pack made up of two or more interconnected batterycells requires the consideration of a cell balance while checking thecapacity, charge/discharge characteristics, and temperature of eachbattery cell, thereby executing charge/discharge control (refer toJapanese Patent Laid-open No. 2002-320334 for example). For this reason,each battery cell has had the wiring dedicated to the obtaining of suchcharge/discharge control data as the cell voltage and temperature shownas enclosed by dashed lines shown in FIG. 1.

SUMMARY

However, as with a large-size battery pack requiring a large capacity,for example, as the number of battery cells increases, the number ofwires for obtaining charge/discharge control data increases, resultingin a battery pack of a complicated structure.

Therefore, the present disclosure addresses the above-identified andother problems associated with related-art methods and apparatuses andsolves the addressed problems by providing a battery, a battery pack, abattery charger, and a battery charging system which are configured toexecute charging and discharging control on the basis of a simplestructure even if the number of battery cells in a battery packincreases.

In carrying out the present disclosure and according to a first modethereof, there is provided a battery. This battery has a contactlesscommunication control block configured to execute contactlesscommunication as a transponder and a reader/writer which are based onelectromagnetic induction; an antenna configured to execute thecontactless communication as the transponder; an antenna configured toexecute the contactless communication as the reader/writer; and abattery control block configured to control a charge operation of a cellblock. In this setup, the contactless communication control blockcommunicates, in a contactless manner, a charge state of the cell blocksupplied from the battery control block.

In the first mode of the present disclosure, the charging of the cellblock is controlled. A charge state of the cell block is communicated bycontactless communication as a transponder and a reader/writer which arebased on electromagnetic induction.

In carrying out the present disclosure and according to a second modethereof, there is provided a battery pack. This battery pack has aplurality of battery cells interconnected in series. Each of theplurality of battery cells has a contactless communication control blockconfigured to execute contactless communication as a transponder and areader/writer which are based on electromagnetic induction; an antennaconfigured to execute the contactless communication as the transponder;an antenna configured to execute the contactless communication as thereader/writer; and a battery control block configured to control acharge operation of a cell block. In this setup, the contactlesscommunication control block communicates, in a contactless manner, acharge state of the cell block supplied from the battery control blockwith the contactless communication control block of the battery celladjacent to one of connection sides of the battery cell.

In the second mode of the present disclosure, two or more battery cellsare interconnected in series. Each of the interconnected battery cellsis controlled in the charging of the cell block. The charge state iscommunicated between the interconnected battery cells by contactlesscommunication as a transponder and a reader/writer which are based onelectromagnetic induction.

In carrying out the present disclosure and according to a third modethereof, there is provided a charger. This charger has a contactlesscommunication control block configured to execute contactlesscommunication as a transponder and a reader/writer which are based onelectromagnetic induction; an antenna configured to execute thecontactless communication as the transponder; an antenna configured toexecute the contactless communication as the reader/writer; and a chargecontrol block configured to control a charge current to be supplied to abattery to be charged. In this setup, the contactless communicationcontrol block communicates a charge state of the battery in acontactless manner and the charge control block controls the chargecurrent in accordance with a charge state of the battery received by thecontactless communication.

In the third mode of the present disclosure, contactless communicationis executed as a transponder and a reader/writer which are based onelectromagnetic induction. The charge state of a battery to be chargedis communicated by contactless communication. In accordance with thecharge state of the battery received by contactless communication, acharge current is controlled.

In carrying out the present disclosure and according to a fourth modethereof, there is provided a charging system. This charging system has abattery pack and a charger. The battery pack has a plurality of batterycells interconnected in series. Each of the plurality of battery cellshas a contactless communication control block of a battery cellconfigured to execute contactless communication as a transponder and areader/writer which are based on electromagnetic induction; an antennaconfigured to execute the contactless communication as the transponder;an antenna configured to execute the contactless communication as thereader/writer; and a battery control block configured to control acharge operation of a cell block. In this setup, the contactlesscommunication control block of the battery cell communicates, in acontactless manner, a charge state of the cell block supplied from thebattery control block with the contactless communication control blockof the battery cell adjacent to one of connection sides of the batterycell. The charger has a contactless communication control block of thecharger configured to execute contactless communication as a transponderand a reader/writer which are based on electromagnetic induction; anantenna configured to execute the contactless communication as thetransponder; an antenna configured to execute the contactlesscommunication as the reader/writer; and a charge control blockconfigured to control a charge current to be supplied to a battery pack.In this setup, the contactless communication control block of thecharger communicates a charge state of the battery pack in a contactlessmanner and the charge control block controls the charge current inaccordance with a charge state of the battery pack received by thecontactless communication.

In the fourth mode of the present disclosure, in the battery pack inwhich two or more battery cells are interconnected in series, each ofthe battery cells is controlled in the charging of the cell block. Thecharge state is communicated between the battery cells by contactlesscommunication as a transponder and a reader/writer which are based onelectromagnetic induction. In the charger, contactless communication isexecuted with the battery pack as a transponder and a reader/writerwhich are based on electromagnetic induction. The charge state of thebattery pack is communicated by contactless communication. In accordancewith the charge state of the battery pack received by contactlesscommunication, a charge current is controlled.

According to the first and second modes of the present disclosure,charge/discharge control can be executed with a simple structure if thenumber of battery cells increases.

According to the third and fourth modes of the present disclosure,charge/discharge control can be properly executed on the battery of thefirst mode or the battery pack of the second mode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a related-art wiring forcharge/discharge control;

FIG. 2 is a schematic diagram illustrating an exemplary configuration ofa charging system practiced as one embodiment of the present disclosure;

FIG. 3 is a schematic diagram illustrating an internal structuresuperimposed on an external view of a battery cell;

FIG. 4 is a schematic diagram illustrating for outlining contactlessnear-field communication;

FIG. 5 is a functional block diagram illustrating an exemplaryfunctional configuration of a battery cell and a battery charger;

FIG. 6 is a schematic diagram for explaining operations of two or morebattery cells which are normally charged;

FIG. 7 is a schematic diagram for explaining operations of two or morebattery cells on which a self-diagnosable trouble has occurred;

FIG. 8 is a schematic diagram for explaining operations of two or morebattery cells on which a non-self-diagnosable trouble has occurred;

FIGS. 9A, 9B, and 9C are schematic diagram illustrating anotherarrangement example of two or more cells; and

FIG. 10 is a schematic diagram for explaining an application example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[Exemplary Configuration of Charging System]

Now, referring to FIG. 2, there is shown an exemplary configuration of acharging system practiced as one embodiment of the present disclosure.

The charging system is made up of a battery pack 2 in which two or morebattery cells 1 are interconnected and a charger 3. In the example shownin FIG. 2, N battery cells 1 are interconnected in series in the batterypack 2. If required, these N battery cells 1 will be described asbattery cells 1-1 through 1-N. The battery pack 2 can be charged ordischarged by loading the battery pack 2 on the charger 3. It should benoted that the charger 3 may be incorporated as a part of an electronicdevice such as a portable personal computer or a digital (video) camera,thereby forming a part of the electronic device along with the batterypack 2.

The battery cell 1 has communication functions as a transponder and areader/writer which are based on electromagnetic induction which arecommunicable in a near-field and contactless manner and receives acharge state of another battery cell 1 adjacent before or after theformer battery cell 1 in contactless communication. In addition, thebattery cell 1 transmits a charge state of its own to another batterycell 1 adjacent before or after the former battery cell 1 along with acharge state received from another battery cell 1 mentioned above.

The charger 3 also has communication functions as a transponder and areader/writer which are based on electromagnetic induction which arecommunicable in a near-field and contactless manner and receives acharge state transmitted from the battery cell 1 to control the chargingof the battery pack 2.

For the near-field and contactless communication as the transponder andreader/writer which are based on electromagnetic induction,communication schemes are available which are compliant with ISO/IEC14443 that is the standard for proximity IC card systems and ISO/IEC18092 that is the standard for NFCIP (Near Field Communication Interfaceand Protocol)-1. The transponder is also called as an IC card, a tag, orRFID (Radio Frequency IDentification). In other words, the communicationfunction as a transponder is representative of the communicationfunction as a card or a tag based on type A, type B of ISO/IEC 14443,FeliCa (trademark), or ISO 15963. However, the communication functionsof the battery cell 1 and the charger 3 are not limited to these typesof standardized contactless near-field communication; namely, thecommunication functions of the battery cell 1 and the charger 3 may bethe contactless near-field communication based on electromagneticinduction with data modulating and communication rate uniquelyspecified.

The battery cell 1 is externally recognizably attached with a label 4written with an ID for identifying the battery cell 1. To be morespecific, battery cells 1-n (n=1, 2, . . . , N) are attached with rebels4 n.

[Exemplary Configuration of Battery Cell]

Referring to FIG. 3, there is shown a schematic diagram illustrating thebattery cell 1 with the internal structure thereof superimposed on theexternal view thereof. The external view of the battery cell 1 is madeup of a top view and a right side view.

The battery cell 1 at least has a contactless communication controlblock 11 and a battery control block 12.

The contactless communication control block 11 controls contactlessnear-field communication as a transponder and a reader/writer which arebased on electromagnetic induction. To be more specific, if operating asa transponder, the contactless communication control block 11 receives acommand from a reader/writer via a transponder antenna 11 _(T). Next,the contactless communication control block 11 returns a response to thereceived command to the reader/writer. In addition, if operating as areader/writer, the contactless communication control block 11 transmitsa predetermined command to another transponder via a reader/writerantenna 11 _(R) on the basis of status data indicative of a charge stateof a cell block 15 supplied from the battery control block 12. Then, thecontactless communication control block 11 receives a response to thepredetermined command from that transponder. It should be noted thateach command transmitted and received by the contactless communicationcontrol block 11 include data which is added to the command from time totime.

The contactless communication control block 11 can be mounted on thebattery cell 1 as an IC chip, for example and may be indicated as a CL(ContactLess) chip 11 in FIG. 4 and subsequent figures. The transponderantenna 11 _(T) is arranged at one end of the length of the battery cell1 and the reader/writer 11 _(R) is arranged at the other end of thelength of the battery cell 1. The reader/writer antenna 11 _(R) is woundaround the cylindrical cell block 15 to form a loop antenna.

The battery control block 12 detects a charge state and a temperaturestate of the cell block 15 in the battery cell 1 to control the batterycell. In accordance with the detected charge state and temperaturestatus of the cell block 15, the battery control block 12 sets a switch13 to “a” side or “b” side. In addition, the battery control block 12supplies status data indicative of the charting state and temperaturestate of the cell block 15 to the contactless communication controlblock 11.

When the switch 13 is set to the “a” side, one cell terminal 15 a of thecell block 15 which is also the negative electrode terminal of thebattery cell 1 is connected to the positive electrode terminal 14 of thebattery cell 1, thereby putting the battery cell 1 into a bypass mode inwhich a charging current from the charger 3 is not supplied to the cellblock 15 of the battery cell 1. On the other hand, when the switch 13 isset to the “b” side, the positive electrode terminal 14 of the batterycell 1 is connected to a cell terminal 15 b which is the other end ofthe cell block 15, thereby putting the battery cell 1 into a normal mode(or charging mode) in which a charging current from the charger 3 issupplied to the cell block 15. It should be noted that the positiveelectrode terminal 14 of the battery cell 1 is completely insulated fromthe cell terminal 15 b of the cell block 15.

The circuit of the switch 13 is configured such that the “b” side,namely, the normal mode is selected by voltage application. Therefore,if the battery control block 12 gets out of control to prevent theapplication of voltage to the switch 13, for example, the switch 13 isset to the bypass mode (namely, the “a” side).

[Outline of the Communication Between Battery Cells 1]

Referring to FIG. 4, there is shown a schematic diagram illustrating anoutline of the contactless near-field communication which is executedbetween the charger 3 and the battery cell 1 or between the batterycells 1.

The battery cell 1-1 receives a command transmitted from a reader/writer21 in the charger 3 via a reader/writer antenna 21 _(R) by contactlessnear-field communication. If no trouble is found, the battery cell 1-1returns a response acknowledging the command received from thereader/writer 21 in the charger 3; if a trouble is found, the batterycell 1-1 returns a trouble code. In addition, the battery cell 1-1transmits status data including a charge state of its own (the batterycell 1-1) to the battery cell 1-2. The battery cell 1-2 receives acommand and status data from the battery cell 1-1 by contactlessnear-field communication. Then, the battery cell 1-2 returns a responseto the battery cell 1-1 and transmits, to the battery cell 1-3 (notshown), status data with a charge state of its own (the battery cell1-2) added to the status data of the battery cell 1-1.

Subsequently, the status data is sequentially relayed between theadjacent battery cells as described above. Next, the battery cell 1-Ntransmits, to a transponder 22 in the charger 3, status data with acharge state of its own (the battery cell 1-N) added to a status datareceived from the battery cell 1-(N−1) by contactless near-fieldcommunication. The transponder 22 in the charger 3 receives the statusinformation transmitted from the battery cell 1-N via a transponderantenna 22 _(T).

It should be noted that a distance between the reader/writer antenna 11_(R) of the battery cell 1 and the transponder antenna 11 _(T) ofanother battery cell 1 between which contactless near-fieldcommunication is executed is in a range with which contactlessnear-field communication of approximately several millimeters to severalcentimeters is practicable. This generally holds true with the adistance between the reader/writer antenna 21 _(R) in the charger 3 andthe transponder antenna 11 _(T) of the battery cell 1-1 and a distancebetween the reader/writer antenna 11 _(R) of the battery cell 1-N andthe transponder antenna 22 _(T) in the charger 3.

In the charging system, only the reader/writer 21 in the charger 3 cangenerate a carrier wave, the other component blocks transmittingcommands by use of the carrier wave generated by the reader/writer 21.To be more specific, the reader/writer 21 in the charger 3 generates acarrier wave and modulates the generated carrier wave by a predeterminedmodulation scheme such as amplitude modulation (ASK) for example,thereby transmitting commands. The contactless communication controlblock 11 of the battery cell 1-1 uses the carrier wave received from thereader/writer 21 to transmit commands to the contactless communicationcontrol block 11 of the battery cell 1-2. Each of the subsequent batterycells 1-2 through 1-N uses the carrier wave received from thereader/writer side to transmit commands.

Consequently, each battery cell 1 need not have an oscillator forgenerating a carrier wave, resulting in the reduced cost of the batterycell 1. In addition, the communication clocks of the battery cells 1 arematched with each other by the carrier wave frequency of thereader/writer 21, thereby achieving synchronization.

[Functional Block Diagram Illustrating Battery Cells and Charger]

Referring to FIG. 5, there is shown a functional block diagramillustrating cells 1-n (n=1, 2, . . . , N) and the charger 3. It shouldbe noted that components similar to those previously described withreference to FIGS. 2 through 4 are denoted by the same referencenumerals and the description thereof will be skipped.

The charger 3 has a contactless communication control block 31, acharging control block 32, and a power supply 33. The contactlesscommunication control block 31 internally has a carrier-wave generatingunit 31 c.

The contactless communication control block 31 corresponds to thereader/writer 21 and the transponder 22 shown in FIG. 4. To be morespecific, If the contactless communication control block 31 operates asa reader/writer, the contactless communication control block 31modulates a carrier wave generated by the carrier-wave generating unit31 c in accordance with a command in a predetermined modulation scheme,transmitting the modulated carrier wave from the reader/writer antenna21 _(R) to the battery cell 1-1. The battery cell 1-1 modulates thecarrier wave outputted from the reader/writer antenna 21 _(R) and thecontactless communication control block 31 receives this modulatedcarrier wave to receive a response from the battery cell 1-1.

If the contactless communication control block 31 operates as atransponder, the contactless communication control block 31 receives,via the transponder antenna 22 _(T), a carrier wave outputted from thereader/writer antenna 11 _(R) of the battery cell 1-N and modulated inaccordance with a command, thereby receiving a command from the batterycell 1-N. In addition, the contactless communication control block 31modulates a carrier wave outputted from the reader/writer antenna 11_(R) of the battery cell 1-N to transmit a response to the battery cell1-N.

Data which is transmitted and received by contactless communicationincludes a command code indicative of the type of command or response, asame ID as that written to label 4 of the battery cell 1, and statusdata indicative of a charge state (a counter to be described later), forexample. If a trouble occurs on the battery cell 1, a trouble codeindicative of the details of a detected trouble for example istransmitted and received. The data to be transmitted and received willbe described later in detail with reference to FIG. 6.

The charge control block 32 controls the supply of the power supply 33on the basis of the charting states of the battery cells 1-1 through 1-Nsupplied from the contactless communication control block 31, therebycontrolling the charging of the battery cells 1-1 through 1-N.

The contactless communication control block 11 of the battery cell 1-noperates as a reader/writer and a transponder like the contactlesscommunication control block 31 of the charger 3. Only difference betweenthe contactless communication control block 11 and the contactlesscommunication control block 31 lies in that, if the contactlesscommunication control block 11 operates as a reader/writer, thecontactless communication control block 11 does not generate a carrierwave on its own but uses a carrier wave generated by the carrier-wavegenerating unit 31 c of the charger 3, thereby transmitting data.

The reader/writer with the battery cell 1-n operating as a transponderbecomes the charger 3 if n=1; if n=2 to N, the reader/writer becomes thebattery cell 1-(n−1). The transponder with the battery cell 1-noperating as a reader/writer becomes the battery cell 1-(n+1) if n=1 toN−1; if n=N, then the transponder becomes the charger 3.

The contactless communication control block 11 obtains status dataindicative of a charge state of the cell block 15 from the batterycontrol block 12 and transmits the status data including a charge stateof its own (the cell block 15) to the following transponder (the batterycell 1-(n+1) if n≠N; the charger 3 if n=N).

The battery control block 12 detects a charge state and a temperaturestate of the cell block 15 to control the cell block 15 and, at the sametime, supplies status data indicative of the detected charge state andtemperature state of the cell block 15 to the contactless communicationcontrol block 11. In addition, in accordance with the detected chargestate and temperature state of the cell block 15, the battery controlblock 12 changes the settings of the switch 13 to the “a” side or the“b” side. It should be noted that the switch 13 shown in FIG. 3 isconventionally divided into a switch 13 x and a switch 13 y in FIG. 5,the switch 13 x and the switch 13 y being controlled in a linked manneras one switch 13.

When the switch 13 is set to the “a” side, then the bypass mode isprovided in which a charging current from the charger 3 is not suppliedto the cell block 15. On the other hand, when the switch 13 is set tothe “b” side, then the normal mode (the charging mode) is provided inwhich a charging current from the charger 3 is supplied to the cellblock 15.

The battery control block 12 can be configured in one IC chip along withthe contactless communication control block 11. In this configuration,the power supplies to the contactless communication control block 11 andthe battery control block 12 may be based on the power generated fromthe carrier wave transmitted from the reader/writer side or the power ofthe cell block 15 of their own.

[Operation to be Executed at Normal Charging]

The following describes operations of the battery cells 1-1 through 1-Nto be executed when these cells are normally charged with reference toFIG. 6.

Each battery cell 1 is not always charged at a same level. In otherwords, the timing with which each battery cell 1 is fully charged isdifferent among the battery cell 1-1 through 1-N. The battery controlblock 12 of each battery cell 1 measures the charging ratio of the cellblock 15 and, when the battery cell 1 has been fully charged, sets theswitch 13 to the “a” side, thereby putting the battery cell 1 into thebypass mode. FIG. 6 shows an example in which the battery cell 1-2 hasbeen fully charged and set in the bypass mode.

The charge control block 32 of the charger 3 causes the contactlesscommunication control block 31 to transmit a command for checking thecharge state. The contactless communication control block 11 of thebattery cell 1-1 receives the command for checking the charge state fromthe contactless communication control block 31 of the charger 3. Thecommand for checking the charge state received from the contactlesscommunication control block 31 is added with a counter with “0” set asthe initial value as data.

The contactless communication control block 11 of the battery cell 1-1receives, from the battery control block 12, status data indicative thatthe cell block 15 of its own (The battery cell 1-1) has not yet beenfully charged but is normally being charged and increments the receivedcounter value by 1. Then, the contactless communication control block 11of the battery cell 1-1 transmits the command for checking the chargestate to the contactless communication control block 11 of the batterycell 1-2 along with the incremented counter.

The contactless communication control block 11 of the battery cell 1-2receives the command for checking the charge state from the battery cell1-1. The status data obtained by the contactless communication controlblock 11 of the battery cell 1-2 from the battery control block 12 isindicative of a fully charge state. In this case, the contactlesscommunication control block 11 of the battery cell 1-2 transmits thecommand for checking the charge state and counter to the contactlesscommunication control block 11 of the battery cell 1-3 by leaving thecounter value unchanged.

As described above, the contactless communication control block 11 ofthe battery cell 1 obtains status data from the battery control block 12of its own and, if the obtained status data is indicative that thebattery cell 1 is being normally charged, increments the counter valueor leaves the counter value unchanged if the battery cell 1 has beenfully charged. Next, the contactless communication control block 11transmits a result of counting processing in accordance with the chargestate to the following battery cell 1. Therefore, if the counterreceived by the contactless communication control block 31 of thecharger 3 from the battery cell 1-N is more than 1, then it indicatesthat at least one of the battery cells 1-1 through 1-N has not beenfully charged. On the other hand, if all of the battery cells 1-1through 1-N are fully charged, then the counter received by thecontactless communication control block 31 of the charger 3 from thebattery cell 1-N is 0.

It should be noted that the transponder side which received the commandfor checking a charge state returns a response indicative of theacknowledgement of the command to the reader/writer side unless notrouble is encountered on the transponder.

As described above, according to the charging system shown in FIG. 2,transmission and reception of status data (charge/discharge controldata) by contactless communication allows the management of thecharge/discharge status of each battery cell 1, so that the related-artwiring for obtaining charge/discharge data becomes unnecessary. To bemore specific, if the number of battery cells 1 increases, charge anddischarge control can be executed on the battery cells 1 with a simplestructure. In addition, the charger 3 can transmit and receivecharge/discharge status of each battery cell 1 to properly executecharge/discharge control.

It should be noted that, in the example mentioned above, one contactlesscommunication control block 11 and one battery control block 12 arearranged for one battery cell 1; it is also practicable to arrange onecontactless communication control block 11 and one battery control block12 for two or more battery cells 1. To be more specific, charge statesmay be managed in units of two or more battery cells to transmit andreceive status data by contactless communication. Further, it is alsopracticable to arrange one contactless communication control block 11and one battery control block 12 for the battery pack 2 in which two ormore battery cells 1 are interconnected and manage the charge state on abattery pack basis, thereby transmitting and receiving status data bycontactless communication. It should be noted however that thischarge/discharge management is executed in units in which the managementis executed by one contactless communication control block 11.

The method in which the counter value 0 or not is transmitted andreceived as described above is a simple method of managing the chargestate of the battery pack 2 by the charge control block 32 of thecharger 3. It is also practicable for the finer management by the chargecontrol block 32 to change the data to be transmitted and received tomore detailed data. For example, the data may be the data itself such asthe charging ratio or the temperature of each battery cell 1. If this ispracticed, no status monitoring wiring is required except for theelectrode connection to result in the simple design of the battery pack2, thereby enhancing the reliability of the battery pack 2 and savingthe manufacturing cost of the battery pack 2.

[Operation to be Executed at Occurrence of Self-Diagnosable Trouble]

The following describes an operation to be executed if aself-diagnosable trouble occurs on the battery cell 1 with reference toFIG. 7. A self-diagnosable trouble denotes a trouble such as anovercurrent or abnormal temperatures about which a trouble code can betransmitted with the contactless communication control block 11 at leastnormally operating, for example.

Referring to FIG. 7, there is shown an example in which aself-diagnosable trouble has occurred on the battery cell 1-2.

Upon detecting a trouble, the battery control block 12 of the batterycell 1-2 sets the switch 13 to the “a” side to set the bypass mode.Next, the battery control block 12 supplies trouble code A indicative oftrouble contents A to the contactless communication control block 11.The contactless communication control block 11 obtains status data inwhich trouble code A is included from the battery control block 12.

The contactless communication control block 11 of the battery cell 1-2returns trouble code A indicative of trouble contents A in which the IDof the troubled battery cell 1-2 is included in response to a commandreceived from the contactless communication control block 11 of thebattery cell 1-1.

At the same time, the contactless communication control block 11 of thebattery cell 1-2 transmits a command for checking a charge state withthe counter value received along with the command unchanged (namely,without incrementing the counter) in the same manner as that of fullcharge to the contactless communication control block 11 of the batterycell 1-3.

Receiving trouble code A of the battery cell 1-2, the contactlesscommunication control block 11 of the battery cell 1-1 returns troublecode A including the ID of the battery cell 1-2 in the nextcommunication with the charger 3. Consequently, the charger 3 can detectthe occurrence of the trouble indicated by trouble code A on the batterycell 1-2. If at least one of the battery cells 1 has a trouble, thecharger 3 may output an alert by such means as an alert light or troublemessage output, for example.

It should be noted that the battery cell 1-2 may return only troublecode A indicative of contents A of an encountered trouble and thebattery cell 1-1 may add the ID of the battery cell 1-2 on which thetrouble occurred to trouble code A and transmit (or return) trouble codeA to the charger 3.

[Operation to be Executed at Occurrence of Non-Self-Diagnosable Trouble]

The following describes an operation to be executed if a trouble whichis not self-diagnosable occurs on the battery cell 1 with reference toFIG. 8. A non-self-diagnosable trouble denotes a trouble which occursnot only on the battery control block 12 but also on the contactlesscommunication control block 11, thereby disabling contactlesscommunication itself.

Referring to FIG. 8, there is shown an example in which anon-self-diagnosable trouble occurred on the battery cell 1-2.

As described above, the circuit of the switch 13 configured to be set tothe “b” side upon voltage application, namely, to select the normalmode. Therefore, if a trouble occurs on the battery control block 12 todisable the control by the battery control block 12, the switch 13 isset to the bypass mode (the “a” side).

If some trouble occurs on the contactless communication control block 11to disable contactless communication itself, then the command forchecking a charge state transmitted from the battery cell 1-1 cannot bereplied.

If no response is made to the command for checking charge state from thebattery cell 1-2, then the contactless communication control block 11 ofthe battery cell 1-1 returns trouble code B of contents B indicative ofno-response including the ID of its own (the battery cell 1-1) in thecommunication with the next charger 3. Consequently, the charger 3 candetect the occurrence of a trouble of trouble code B in the battery cell1-2 next to the battery cell 1-1.

In this case, the command for checking charge state is not transmittedto the battery cells 1-3 through 1-N following the battery cell 1-2.However, the switch 13 of the battery cell 1-2 is in the bypass mode,the charge current from the charger 3 is also supplied to the batterycells 1-3 through 1-N. Each of the battery cells 1-3 through 1-Nuniquely manages the charge state as “temporary mode.”

As described above with reference to FIGS. 7 and 8, if a trouble isdetected on any one of the battery cells 1-1 through 1-N, the charger 3can recognize the contents of the detected trouble and failed batterycell 1 by contactless communication. The charger 3 which recognized theoccurrence of the trouble can display the trouble code indicative of thecontents of the detected trouble and ID of the failed battery cell 1onto a predetermined display block. Consequently, the user whorecognized the display of the failed battery cell 1 on the predetermineddisplay block can compare the battery cell 1 with the ID of label 4attached to the outside of the battery cell 1 to replace the failedbattery cell 1, for example. Therefore, only the failed battery cell 1can be replaced with ease, thereby simplifying the repair work. Itshould be noted that, instead of recognizing the failed battery cell 1by the ID of label 4 attached to the outside of the battery cell 1, thefailed battery cell 1 may be identified by turn-on of a light which iscostlier than the label ID recognition.

[Exemplary Arrangement of Battery Cells]

Referring to FIGS. 9A, 9B, and 9C, there are shown another exemplaryarrangement of two or more battery cells.

In the example shown above, N battery cells 1-1 through 1-N are arrangedin one row connected with each other in series. However, two or morebattery cells 1 making up the battery pack 2 may be arranged in anothermanner; two or more rows of two or more battery cells 1 interconnectedin series are arranged vertically to the length direction as shown inFIGS. 9A through 9C, for example.

FIGS. 9A and 9B show examples in which N battery cells 1-1 through 1-Nare arranged in two rows in parallel, each row having N/2 battery cells.FIG. 9A shows an example in which the adjacent rows is shifted in thelength direction by about a half of the cell length of the battery cell1. FIG. 9B shows an example in which the adjacent rows are arranged atthe same position in the length direction.

In the exemplary arrangements shown in FIGS. 9A and 9B, the distancebetween the reader/writer antenna 11 _(R) and the transponder antenna 11_(T) which communicate each other in a contactless manner is distanceDS1 less than the maximum value of communicable distance (hereafterreferred to as a maximum communication distance) Lmax. On the otherhand, the distance between the reader/writer antenna 11 _(R) and thetransponder antenna 11 _(T) which do no communicate each other in acontactless manner is distance DS2 sufficiently greater than the maximumcommunication distance Lmax at the nearest.

FIG. 9C shows an example in which N battery cells 1-1 through 1-N arearranged in two rows in parallel, each row having N/2 battery cells, anda separator SP is arranged between the adjacent rows in order to preventthe interference of electromagnetic waves (carrier waves). In this case,the distance between the adjacent rows can be made smaller than that ofthe arrangement shown in FIG. 9B. The separator SP may be a shield.

In the examples mentioned above, the distance between the reader/writerantenna 11 _(R) and the transponder antenna 11 _(T) was described. It isobvious that the same holds with the distance between the transponderantenna 22 _(T) of the charger 3 and the reader/writer antenna 21 _(R).

It should be noted that, in the examples shown above, whether chargelines for the battery cells 1 arranged in two parallel rows areinterconnected in parallel or series was not described. A method ofcharge line connection may be appropriately determined in accordancewith necessary capacity and voltage. It should be noted that thecontactless near-field communication is executed in units of one row.

The maximum communication distance Lmax depends on the diameter andmagnetic field strength of the reader/writer antenna 11 _(R) which is aloop antenna. The diameter of the reader/writer antenna 11 _(R) isnecessarily determined to be the diameter of the cell block 15+α(>0) andcannot be changed because the reader/writer antenna 11R is wound aroundthe external periphery of the cylindrical cell block 15. Hence, themaximum communication distance Lmax is determined by appropriatelysetting the magnetic field strength.

[Exemplary Applications]

If a trouble or troubles occur on one or more battery cells 1-1 through1-N interconnected in series to make the failed battery cell or cellsunusable, namely, if one or more battery cells 1-1 through 1-N haveentered the bypass mode, then the output voltage of the battery pack 2at the time of discharge drops.

In order to prevent this problem, a voltage regulator 51 can be arrangedas shown in FIG. 10 to raise the voltage dropped by the bypass mode tothe same level as the normal voltage level and output the regulatedvoltage. This arrangement allows the use of the power supply of thebattery pack 2 as “temporary mode” if a trouble occurs on the batterycell 1 to cause a voltage drop. The coverage of the voltage regulator 51over voltage drops can be appropriately determined in accordance withhow many failed battery cells 1 are allowed. The voltage regulator 51may be arranged in either the charger 3 or the battery pack 2.

Term “system” herein denotes an entire apparatus made up of two or moreapparatuses.

While preferred embodiments of the present disclosure have beendescribed using specific terms, such description is for illustrativepurpose only, and it is to be understood that changes and variations maybe made without departing from the spirit or scope of the followingclaims.

The present technology contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2011-030057 filed in theJapan Patent Office on Feb. 15, 2011, the entire content of which ishereby incorporated by reference.

What is claimed is:
 1. A battery comprising a plurality of battery cells interconnected in series, each battery cell having: a contactless communication control block configured to execute contactless communication as a transponder and a reader/writer based on electromagnetic induction; a first antenna configured to execute the contactless communication as the transponder; a second antenna configured to execute the contactless communication as the reader/writer; and a battery control block configured to control a charge operation of a cell block; wherein, the contactless communication control block communicates, in a contactless manner, a charge state of the cell block supplied from the battery control block with the contactless communication control block of the battery cell adjacent to one of the connection sides of the cell block, and the first antenna is arranged at one end portion of the battery and the second antenna is arranged at an opposite end portion of the battery with respect to a length direction of the battery.
 2. The battery according to claim 1, further comprising a switch configured to switch between a normal mode in which a charge current is supplied from a charger to the cell block and a bypass mode in which the cell block is bypassed, the battery control block also controlling the switch.
 3. The battery according to claim 2, wherein the switch is set to the bypass mode when no voltage is applied.
 4. The battery according to claim 1, wherein the contactless communication control block transmits data by using a carrier wave received when the contactless communication control block operates as the transponder as a carrier wave for use when the contactless communication control block operates as the reader/writer.
 5. The battery according to claim 1, wherein the battery is a battery pack.
 6. A battery pack comprising: a plurality of battery cells interconnected in series; each of the plurality of battery cells having (a) a contactless communication control block configured to execute contactless communication as a transponder and a reader/writer that are based on electromagnetic induction, (b) a first antenna configured to execute the contactless communication as the transponder, (c) a second antenna configured to execute the contactless communication as the reader/writer, and (d) a battery control block configured to control a charge operation of a cell block, wherein, the contactless communication control block communicates, in a contactless manner, a charge state of the cell block supplied from the battery control block with the contactless communication control block of the battery cell adjacent to one of connection sides of the battery cell.
 7. The battery pack according to claim 6, wherein the first antenna is arranged at one end of each of the plurality of battery cells and the second antenna is arranged at another end of each of the plurality of battery cells.
 8. The battery pack according to claim 6, wherein a plurality of rows of two or more battery cells interconnected in series are arranged perpendicular to a length direction of the plurality of battery cells.
 9. The battery pack according to claim 8, wherein the plurality of rows of two or more battery cells arranged perpendicular to the length direction of the plurality of battery cells are shifted adjacently from each other in the length direction.
 10. The battery pack according to claim 8, wherein a separator is arranged between the plurality of rows of two or more battery cells arranged perpendicular to the length direction of the plurality of battery cells.
 11. The battery pack according to claim 6, wherein each of the plurality of battery cells includes a switch for switching between a normal mode in which a charge current from a charger is supplied to the cell block and a bypass mode in which the cell block is bypassed, the switch being set to the bypass mode when no voltage is applied.
 12. The battery pack according to claim 11, further comprising: a voltage regulator configured to make constant a voltage to be outputted to outside.
 13. A charging system comprising: a battery pack; and a charger, wherein, the battery pack includes a plurality of battery cells interconnected in series, each of the plurality of battery cells having (a) a contactless communication control block of a battery cell configured to execute contactless communication as a transponder and a reader/writer which are based on electromagnetic induction, (b) a first antenna configured to execute the contactless communication as the transponder, (c) a second antenna configured to execute the contactless communication as the reader/writer, and (d) a battery control block configured to control a charge operation of a cell block, the contactless communication control block of the battery cell communicating, in a contactless manner, a charge state of the cell block supplied from the battery control block with the contactless communication control block of the battery cell adjacent to one of connection sides of the battery cell, and the charger includes (a) a contactless communication control block of the charger configured to execute contactless communication as a transponder and a reader/writer which are based on electromagnetic induction, (b) a third antenna configured to execute the contactless communication as the transponder, (c) a fourth antenna configured to execute the contactless communication as the reader/writer, and (d) a charge control block configured to control a charge current to be supplied to a battery pack, the contactless communication control block of the charger communicating a charge state of the battery pack in a contactless manner, the charge control block controlling the charge current in accordance with a charge state of the battery received by the contactless communication.
 14. The charging system of claim 13, wherein each battery cell further comprises a switch configured to switch between a normal mode in which a charge current is supplied from a charger to the cell block and a bypass mode in which the cell block is bypassed, the battery control block also controlling the switch.
 15. The charging system of claim 14, wherein the switch is set to the bypass mode when no voltage is applied.
 16. The charging system of claim 13, wherein the contactless communication control block of each battery cell transmits data by using a carrier wave received when the contactless communication control block of the battery cell operates as the transponder as a carrier wave for use when the contactless communication control block operates as the reader/writer. 